William Blair Investment Management, LLC reported 392 positions worth $33.15B for the quarter ended Jun 30, 2026, up 10.4% on the prior quarter. It opened 45 new positions, added to 115, trimmed 225 and exited 50. Its largest holding is Taiwan Semiconductor Manufacturing Co Ltd at 7.1% of the portfolio.
Reported 13F market value at each quarter end. A change mixes trading with price moves in the positions held.
Dollar value of shares bought and sold each quarter, at that quarter’s price. It counts trading only, not price changes.
How many positions were opened, added to, trimmed or closed each quarter.
Share of reported value in each sector at every quarter end.
| Holding | Change | Trade Value | Weight |
|---|---|---|---|
| AMAT Applied Materials Inc | +463.0K +1,325.1% | $334.75M | 1.09% |
| GE General Electric Co | +790.8K | $295.55M | 0.892% |
| GOOGL Alphabet Inc. | +686.4K +27.4% | $245.30M | 3.44% |
| CRWD CrowdStrike Holdings, Inc. | +1.13M | $214.75M | 0.648% |
| STX Seagate Technology Holdings plc | +190.8K | $184.17M | 0.556% |
| TEVA Teva Pharmaceutical Industries Ltd | +5.17M +362.5% | $175.07M | 0.674% |
| CNQ CANADIAN NATURAL RESOURCES Ltd | +3.64M | $143.70M | 0.433% |
| FPS Forgent Power Solutions, Inc. | +2.52M | $140.56M | 0.424% |
| PTCT Ptc Therapeutics, Inc. | +1.72M | $140.52M | 0.424% |
| TKR Timken Co | +949.7K +18,347.4% | $138.01M | 0.419% |
| Holding | Change | Trade Value | Weight |
|---|---|---|---|
| AAPL Apple Inc. | -1.55M -32.3% | $449.24M | 2.85% |
| TWST Twist Bioscience Corp | -3.10M -58.7% | $318.43M | 0.675% |
| MSFT Microsoft Corp | -848.1K -29.3% | $316.37M | 2.31% |
| AMZN Amazon Com Inc | -1.18M -37.2% | $280.42M | 1.43% |
| TSM Taiwan Semiconductor Manufacturing Co Ltd | -581.9K -10.5% | $277.86M | 7.11% |
| TECH BIO-TECHNE Corp | -2.46M -99.8% | $173.69M | <0.01% |
| AMD Advanced Micro Devices Inc | -279.1K -26.8% | $162.12M | 1.34% |
| COHR Coherent Corp. | -668.1K -100.0% | $159.16M | Exited |
| DCI DONALDSON Co INC | -1.58M -97.8% | $141.87M | <0.01% |
| LSCC Lattice Semiconductor Corp | -883.3K -43.2% | $135.11M | 0.535% |
| Holding | Shares | Trade Value | Weight |
|---|---|---|---|
| GE General Electric Co | +790.8K | $295.55M | 0.892% |
| CRWD CrowdStrike Holdings, Inc. | +1.13M | $214.75M | 0.648% |
| STX Seagate Technology Holdings plc | +190.8K | $184.17M | 0.556% |
| CNQ CANADIAN NATURAL RESOURCES Ltd | +3.64M | $143.70M | 0.433% |
| FPS Forgent Power Solutions, Inc. | +2.52M | $140.56M | 0.424% |
| PTCT Ptc Therapeutics, Inc. | +1.72M | $140.52M | 0.424% |
| ETSY Etsy Inc | +1.60M | $120.42M | 0.363% |
| RGEN Repligen Corp | +788.6K | $107.59M | 0.325% |
| HBM Hudbay Minerals Inc. | +4.22M | $99.54M | 0.3% |
| AAOI Applied Optoelectronics, Inc. | +504.2K | $74.70M | 0.225% |
| Holding | Shares Sold | Trade Value | Prior Weight |
|---|---|---|---|
| COHR Coherent Corp. | -668.1K | $159.16M | 0.53% |
| VEEV Veeva Systems Inc | -643.3K | $113.01M | 0.376% |
| DOCS Doximity, Inc. | -4.83M | $112.64M | 0.375% |
| PLNT Planet Fitness, Inc. | -1.45M | $108.05M | 0.36% |
| POOL Pool Corp | -452.3K | $91.51M | 0.305% |
| WMS Advanced Drainage Systems, Inc. | -655.7K | $89.91M | 0.299% |
| PSN Parsons Corp | -1.49M | $80.58M | 0.268% |
| TYL Tyler Technologies Inc | -215.7K | $73.87M | 0.246% |
| INSP Inspire Medical Systems, Inc. | -1.14M | $58.67M | 0.195% |
| SPOT Spotify Technology S.A. | -106.9K | $51.86M | 0.173% |
| # | Activity | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | TSM Taiwan Semiconductor Manufacturing Co Ltd | Technology | 4.94M | $2.36B | 7.11% | -581.9K | -10.5% | Reduced | 0.1% |
| 2 | NVDA Nvidia Corp | Technology | 8.60M | $1.72B | 5.19% | -342.7K | -3.8% | Reduced | 0.04% |
| 3 | GOOGL Alphabet Inc. | Technology | 3.19M | $1.14B | 3.44% | +686.4K | +27.4% | Added | 0.05% |
| 4 | AAPL Apple Inc. | Technology | 3.26M | $943.29M | 2.85% | -1.55M | -32.3% | Reduced | 0.02% |
| 5 | AVGO Broadcom Inc. | Technology | 2.06M | $776.71M | 2.34% | -145.4K | -6.6% | Reduced | 0.04% |
| 6 | MSFT Microsoft Corp | Technology | 2.05M | $764.18M | 2.31% | -848.1K | -29.3% | Reduced | 0.03% |
| 7 | META Meta Platforms, Inc. | Technology | 950.1K | $535.19M | 1.61% | -63.0K | -6.2% | Reduced | 0.04% |
| 8 | AMZN Amazon Com Inc | Consumer Discretionary | 1.99M | $473.60M | 1.43% | -1.18M | -37.2% | Reduced | 0.02% |
| 9 | MA Mastercard Inc | Financial Services | 918.0K | $471.49M | 1.42% | -142.6K | -13.4% | Reduced | 0.11% |
| 10 | AMD Advanced Micro Devices Inc | Technology | 763.5K | $443.53M | 1.34% | -279.1K | -26.8% | Reduced | 0.05% |
| 11 | AMAT Applied Materials Inc | Technology | 497.9K | $360.01M | 1.09% | +463.0K | +1,325.1% | Added | 0.06% |
| 12 | GE General Electric Co | Industrials | 790.8K | $295.55M | 0.892% | +790.8K | – | New | 0.08% |
| 13 | AZN Astrazeneca Plc | Healthcare | 1.51M | $283.25M | 0.855% | -427.4K | -22.0% | Reduced | 0.1% |
| 14 | PRMB Primo Brands Corp | Consumer Staples | 11.43M | $279.27M | 0.843% | -1.63M | -12.5% | Reduced | 3.15% |
| 15 | P Everpure, Inc. | Technology | 3.46M | $272.25M | 0.821% | +573.9K | +19.9% | Added | 1.04% |
Tip. Select a row to see that position’s full history at William Blair Investment Management.
As of its Q2 2026 13F filing, William Blair Investment Management, LLC’s five largest positions were Taiwan Semiconductor Manufacturing Co Ltd (TSM) at 7.1%, Nvidia Corp (NVDA) at 5.2%, Alphabet Inc. (GOOGL) at 3.4%, Apple Inc. (AAPL) at 2.8%, Broadcom Inc. (AVGO) at 2.3% of the reported portfolio.
William Blair Investment Management, LLC reported a 13F portfolio worth $33.15B across 392 positions for Q2 2026. That is up 10.4% from the previous quarter.
Its largest purchases by value were Applied Materials Inc ($334.75M), General Electric Co ($295.55M), Alphabet Inc. ($245.30M). It opened 45 new positions.
Its largest sales by value were Apple Inc. ($449.24M), Twist Bioscience Corp ($318.43M), Microsoft Corp ($316.37M). It exited 50 positions entirely.
From the Form 13F-HR reports William Blair Investment Management, LLC files with the SEC each quarter, within 45 days of quarter end. A 13F lists long positions in US-listed equities and options; it excludes short positions, cash, bonds and most non-US holdings.
13F data reflects long positions in US-listed equities and options as reported to the SEC up to 45 days after quarter end. It excludes short positions, cash, bonds and most non-US securities, so it is not a complete picture of a manager’s assets.